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Your rig CANT handle this!

Last response: in Graphics & Displays
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May 3, 2011 1:43:30 PM

Everyone always says FSX (Flight Simulator X) is more CPU than GPU limited, but can anyone who REALLY knows what they are talking about explain why?

I wonder if the new version of flight simulator will take advantage of the latest GPU capabilities and end this frustration once and for all!

I have I have an i7 overclocked to 4ghz with two new GTX 560ti's running in SLI mode and I'll be dammed, they were right! My significant investment in faster video cards DIDN'T pay off! Theoretically my new setup is 2x faster than my previous video card setup (2 ati 5670's in crossfire) however, my FSX frame-rate hardly budged!

Keep in mind I am flying in Chicago with the cities - x addon for Chicago which brings some people down to 5 FPS! I'm still at about 20 FPS on multiple 1920 x 1080 screens, but this is still a bit choppy.

It always makes me laugh to see people comparing Crysis and Metro 2033 and complaining about "only" getting 50 FPS because of how demanding they are. ***, id be ecstatic with 35 FPS on Flight Simulator X. FSX brings a computer to knees more than any other game out there BY FAR!

Anybody with good solutions please reply!!!

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a c 271 U Graphics card
May 3, 2011 5:36:09 PM

Does FSX use SLi?
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a b U Graphics card
May 3, 2011 5:49:34 PM



Im betting at a higher resolution, your cpu wouldn't be the bottleneck and you'd see more from your cards. I also wonder if 2gb 6950's would have been the way to, not sure how more vram would affect it.

What cpu do you have? Have you tested to see if it is a cpu bottleneck? I mean do you see a big increase from your i7 at stock than you do at 4ghz?

How much system ram?
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a b U Graphics card
May 3, 2011 8:51:28 PM

I would say maybe you are running out of vRAM. Your CPU is fast, and your GTX 560 Tis should be 4x faster than your hd5670s in CF. If it doesn't SLi, that would be your issue.
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a b U Graphics card
May 3, 2011 8:53:31 PM

From what I read, It doesn't support SLi. Sorry.
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a c 271 U Graphics card
May 3, 2011 8:56:33 PM

HostileDonut said:
From what I read, It doesn't support SLi. Sorry.

If FSX does not support SLi by default then it may be possible to 'force it' via the Nv control panel but results may vary.
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a c 216 U Graphics card
May 3, 2011 9:07:18 PM

One problem that you are running into is that FSX has a 20 FPS cap. It will not allow higher.

I think I've heard someone mention there is a way to remove it, but you'll have to search for a way to remove the FPS cap.
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May 4, 2011 11:43:37 AM

I appreciate the comments, although I am aware of the 20 FPS default and have already changed it.

If I am only running on one screen I get reasonable performance. Its when I am trying to run on 3 screens in a "wrap around" setup that it kills it.

I have researched this a little more with the help from the guys at jetlinesystems.com and they have confirmed that its a CPU bottleneck. The best graphics card in the world cant fix this one.

http://www.jetlinesystems.com/performance.html

As they show, 75% of FSX framerate comes from the CPU and not GPU. However, FSX SP2 does make use of multicores so I could build a rig with the latest 990 extreme i7 with 6 cores (instead of my current 4). Not sure Im ready to spend THAT much on the habit yet!

Thanks again for the feedback...
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a b U Graphics card
May 4, 2011 11:57:17 AM

FSX is far more CPU limited, which considering the type of game it is, makes sense. To compute the physics involved in flight for a large amount of aircraft [even as dumbed down as most physics engines are] over a large distance takes a LOT of power to do well.

FSX is the poster child for a game that would run a heck of a lot better with GPU enabled PhysX in my mind; I'd love to see how it ran with GPU's doing most of the physics calcuations...
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a c 216 U Graphics card
May 4, 2011 3:07:12 PM

gamerk316 said:
FSX is far more CPU limited, which considering the type of game it is, makes sense. To compute the physics involved in flight for a large amount of aircraft [even as dumbed down as most physics engines are] over a large distance takes a LOT of power to do well.

FSX is the poster child for a game that would run a heck of a lot better with GPU enabled PhysX in my mind; I'd love to see how it ran with GPU's doing most of the physics calcuations...


While this is true, it doesn't make sense that multiple monitors would require more CPU power. The physics are the same regardless.
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a b U Graphics card
May 4, 2011 4:39:59 PM

Quote:
While this is true, it doesn't make sense that multiple monitors would require more CPU power


More devices need to be managed, more pixels need to be mapped, etc. That affects a lot of low level Windows stuff, even if a lot of work is also added to the GPU. I would expect that multi-moniter would be more GPU limited, but the CPU would get its share of the increase as well, and with FSX already been serverly CPU limited...
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a c 171 U Graphics card
May 5, 2011 3:55:03 AM

bystander said:
While this is true, it doesn't make sense that multiple monitors would require more CPU power. The physics are the same regardless.

when there is a wider field of view to be rendered then more cpu power is required. Multiple monitors gives you a wider field of view (more objects in view). Its different from increasing resolution with a fixed aspect ratio where the field of view remains the same which would not affect the cpu, only gfx card.
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a c 216 U Graphics card
May 5, 2011 4:08:44 AM

iam2thecrowe said:
when there is a wider field of view to be rendered then more cpu power is required. Multiple monitors gives you a wider field of view (more objects in view). Its different from increasing resolution with a fixed aspect ratio where the field of view remains the same which would not affect the cpu, only gfx card.


In a realistic flight simulator, exactly what all are you having to calculate physics for? All the physics that are calculated, wouldn't they be of the aircraft you are flying, and occasionally another aircraft near by, unless you are landing, you may see more airport, but I wouldn't think something inanimate would require physics calculations.

Obviously it does use more CPU power, but I just didn't really think there would be much in the way of increased physics calculations for this type of game.
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a b U Graphics card
May 5, 2011 11:54:51 AM

Keep in mind, its not like if its off the screen, its details are not computed. FOV only affects what the GPU is rendering now, so a wider FOV is much more GPU limited then CPU limited. Just because objects exist outside the immediate FOV does not mean they do not exist.

FOV only affects GPU rendering; objects outside the immediate FOV still exist, need AI updates, and in most cases have effects on shading inside the FOV [say, if you are standing with your back to a Tree; the trees shadow still needs to be computed, even though the tree is outside the FOV].
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May 5, 2011 12:37:58 PM

Why is the game capped at 20fps?
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a c 216 U Graphics card
May 5, 2011 3:36:45 PM

iam2thecrowe said:
i didnt say physics, but the cpu still has to pass on the details of all the extra objects the gpu needs to render so it needs to do more work.
see this link for more about the 3d rendering process and what part the cpu plays in it http://www.tomshardware.com/forum/314729-33-rendering-w...


You might not have, but the post everyone kept quoting of mine, was from a quote referring to having to calculate more physics.
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